[78-L] Acoustic recording

[Michael Shoshani]

On Tue, 2011-06-28 at 08:35 -0700, DAVID BURNHAM wrote:
> Does anyone know if, when recording acoustically, the sound was applied to the side of the cutting diaphragm facing the edge of the record or the side facing the centre spindle?

Engravings of Berliner's experimental apparatus show the recording
funnel hitting the diaphragm on the side facing the edge of the record,
and I would presume that that's the way it stayed. 

Not only is that easier to work with (the diaphragm input isn't
suspended over the wax), it also ensures that the playback is in phase,
since the reproducing diaphragm will send its output through the spindle
side. Thus, it's as though the original sound wave simply passed
through, preserving the peaks and troughs rather than inverting them.

But that's only a guess. I've never seen an acoustic recording setup,
and would suppose that most of them were done away with when they became
obsolete. One may still exist as a curio in the EMI Archive, but I don't
think anyone from there is on 78-L.

MS